The engine identification code consists of the
engine assembly plant, the engine assembly date, and a 2 or 3 letter
suffix indicating the cubic inch displacement, the horsepower rating,
and generally, what type of transmission was to be installed with the
engine. Manual transmissions required a bushing in the rear of the
bellhousing where an automatic transmission did not. Many engine
"accessories" such as the carburetor, distributor, and exhaust manifolds
were not installed at the engine assembly plant but rather at the final
assembly plant.